I got confused then sorted it out. I’ll drop a note to anyone coming later to a similar problem.
“Make PostProcessingSettings” has the arrow on the bottom that allows me to collapse the node. But using it’s output in a “Set Settings” applies all the hidden parameters too.
“Set members in PostProcessingSettings” does not have that arrow to colapse as I understood from Damato, but instead of unchecking all the unwanted parameters on the detail list, you can right-click a parameter on the node and chose “Remove all other pins”. Then if you want a couple parameters back on, you can turn them on in the details.